This invention relates generally to signaling devices of the type which indicate when the door of a mailbox has been opened and mail is present in the box. It is desirable that a remotely visible flag or other such signaling means be automatically displayed in response to opening of the door so that the mail carrier has no responsibility for actuating the signaling device. It is also desirable that the device be easily reset or cocked after the addressee removes the delivered items from the box without employing both hands in the resetting operation.
One prior art signaling device which incorporates the desirable features noted above is disclosed in U.S. Pat. No. 3,084,853 issued to P. E. Kopp on Apr. 9, 1963. Kopp shows an elongated signal arm pivotably mounted on a mailbox and swingable from a cocked horizontal position to a tripped vertical position. The non-signaling end of Kopp's arm carries a pawl which interfers with a strike bracket mounted on the box door whereby the arm is maintained in a horizontal position until the door is swung open. Upon opening the door, the arm is pivoted downwardly by gravitational force operating on a pair of weights attached to the non-signaling end of the arm. The first weight causes the arm to pivot to an upright or vertical signaling position while the second weight, due to a different moment arm, urges the arm against a stop to maintain its vertical orientation. To reset the Kopp device the signal arm is swung manually back to a horizontal position whereby the pawl, which is pivotably linked to the first weight, strikes the strike bracket and pivots about the non-signaling end of the arm to override the strike bracket there by assuming the cocked position.
While the Kopp device does provide automatic, gravity actuated signaling and resetting can be accomplished with only one hand, this device is overly complicated from a structural standpoint and is, therefore, unnecessarily costly to manufacture. Thus Kopp requires a pair of weights and means for individually mounting the same on his signal arm. Also complicating Kopp's device is the reset pawl which is pivotalby attached to the signal arm and is also pinned to a strap which carries one of the weights.